Butane carburetion



prll 28, 1953 J. F. ARMSTRONG ET AL 2,636,814

L BUTANE CARBURETION Filed Dec. 23, 1946 4 Sheets$heet l FIG.2.

INVENTORS JAMES F. ARMSTRONG BYJAMES T. w. MOSELEY ATTORNEY 4 Sheets-Sheet 2 BUTANE CARBURETION J. F. ARMSTRONG ET AL A ril 28, 1953 Filed Dec.

INVENTORS JAMES F. ARMSTRONG JAMES T.W. MOSELEY ATTORNEY April 8, 1953 J. F. ARMSTRONG ET AL 2,636,814

BUTANE CARBURETION 4 Sheets-Sheet 5 Filed Dec. 23, 1946 FIGS.

INVENTORS M S F. ARMSTRONG JAMES T. W.MOSELEY BY JAE $51M ATTORNEY April 28, 1953 J. F. ARMSTRONG ET AL 2,636,814

BUTANE CARBURETION 4 Sheets-Sheet 4 Filed Dec. 23, 1946 FIG-.7.

I INVENTORS JAMES F. ARMSTRONG Y JAMES T.W.MOSELEY ATTORNEY Patented Apr. 28, 1953 BUTANE CARBURETION James F. Armstrong, Detroit, Mich, and James T. W. Moseley, Clayton, Mo., assignors to Carter Carburetor Corporation, St. Louis, Mo, a corporation of Delaware Application December 23, 1946, Serial No. 717,932

Glaims.

This invention relates to fuel feed apparatus for internal combustion engines and consists particularly in a novel regulator, heater, and carburetor apparatus for supplying to the engine a normally gaseous fuel, such as butane, which is stored in a tank under relatively high pressure.

As the supply of stored gas, usually in a liquid condition, is depleted, the delivery pressure decreases and it is the function of the regulator to insure the delivery of fuel to the carburetor at a uniform, usable pressure notwithstanding. Where the engine operates at variable speeds and under variable loads, as is the case with an automotive engine, a simple pressure reducing valve will not do the work because of the decreasing delivery pressure as well as the widely varying pressures in the carburetor itself, particularly, where the main fuel nozzle is located anterior to the throttle, as is customary. Moreover, the expansion of the gases as they pass the reducing valve of the regulator results in cooling which may cause recondensation of a portion of the gases and it is necessary to overcome such recondensation.

Accordingly, it is an object of the present invention to provide a novel regulator and carburetor apparatus of the above-mentioned type of service which is constructed to supply the right proportions of fuel and air under all condiions of operation.

It is another object to provide such an apparatus with effective means for increasing the supply of fuel. for starting.

It is another object to provide such an apparatus in which. a volume of fuel under slight superatmospheric pressure is maintained in immediate proximity to the carburetor nozzle during idling so that this volume of fuel is available for supply to the carburetor upon acceleration even before the regulator can readjust itself.

It is another object to provide a carburetor of the above type having a starting adjustment which is universal to the extent that the positioning of the carburetor may be widely varied in use without the necessity of reconstructing any part thereof.

These objects and other more detailed objects hereafter appearing are attained by the apparatus illustrated in the accompanying drawings in which Fig. 1 is a perspective view of an automotive engine having the novel fuel supply apparatus applied thereto.

Fig. 2 is an enlarged side View of the carburetor.

Fig. 3 is a diagrammatic View of the apparatus illustrating the manner of connecting the various parts.

Fig. 4 is a view of the carburetor looking at the opposite side from Fig. 2.

Fig. 5 is a top view of the carburetor, a portion being broken away substantially on line 5-5 of Fig. 7 for clearer illustration.

Fig. 6 is a vertical central section through the carburetor taken substantially on line 6-45 of Fig. 5.

Fig. 7 is an elevation viewed substantially from line 1-'l of Fig. 5 with a, portion removed for clearer illustration.

Figure 1 shows an internal combustion engine If of the automotive type mounted between the dash panel i3 and the usual cooling radiator M, the latter being connected to the engine water chamber by piping i5 and it. The cooling fan I! is mounted on a shaft 18 extending from the water pump housing [9. A tank it is conveniently mounted for storing normally gaseous fuel, such as butane, under such relatively high pressure as to be initially in a liquid condition. Safety valve 2! of the type illustrated in a copending application, Serial No. 734,433, filed March 13, 1947, in the names of James T. W. Moseley and James F. Armstrong, is mounted on the dash and interposed in feed line 22 from tank 20. Line 22 connects with the regulator generally indicated at 23, also mounted on the dash. Carburetor 24 is mounted on intake manifold 25, both the carburetor and manifold forming part of the induction conduit system of the engine. The carburetor is of the downdraft type, but may be arranged for updraft or side draft operation. Hot water lines 26 and 21 extend from the regulator to the engine water jacket and a gas feed line 28 connects the regulator and carburetor. A suction line 29 and an atmospheric vent line 35 also connect the regulator and carburetor.

The carburetor, as more clearly illustrated in Figs. 2, 4, 5, 6, and 7 is of the downdraft type having an upper air inlet portion 35, a central Venturi tube 36, and an outlet portion 3'5, flanged as at 38 fOr attachment to the intake manifold. A butterfly throttle 39 mounted on shaft it controls the delivery of mixture through the engine. One or more slots H formed in the throat of Venturi tube 35 connects an annular space 42 around the Venturi tube with the anterior of the carburetor and constitute fuel supply nozzles. A cup-shaped casing structure 5i on the right side of the carburetor barrel (Fig. 6) has generally tubular extension 52 forming a fuel ante-chamber 53. This chamber is connected to annular passage 52 through a calibrated orifice member -3 formed in the side of the carburetor barrel and variably restricted by a tapered metering valve 55. Valve 55 has a threaded stem 55a, carried by a lever 56 rigid on a shaft 51 journalled in a tubular boss 58 and extending through the wall of casing 5! (Fig.7). .Lsver ethassan'npward extension 59 with a lateral pin Eil-receivedin a slot 6! formed by the folded over extremity of a strap 63. This strap at its outer end is comnected to a diaphragm 6 1 received between a shoulder on casing extension 52 and "a small cap (it. This diaphragm .isconstantly,iurged to the left by a coiled spring .61 and itslmaximum rightward movement is limited .by a :screw Chamber 89 formed by cap 66 and the diaphragm is connected to suction port ill posterior .to throttle 39: by means of passages "H and 72 (Figs 2 and 7). Fuel ante-chamber 53 is provided with an inlet connection boss 13 and a lay-pass M, controlled by adiustingscrew-H which provides for supplying idling fuel to the carburetor mixture conduit posterior to .the throttle. Thisidling. bypass may be eliminated,.aswilhbeexplainedihera after, in which .caseidlingifuel wouldbe supplied through. main. fueLorificeM andnozzles-M Projecting into the =inlet.end.of the carburetor barrel is an air tube .15 which: connects with an elongated boss l'lonthe outside-of .the carburetor barrel and having a threaded opening for connection .to .air vent-tubeasil gpreviously men tioned. .Projecting fromicasinge'il opposite boss "i1 is a second boss tlfhaving athreaded opening 3 ior connection to .suction .line 38,; previously mentioned. .A passage .82 .(Eigli) extends centrally and horizontally. throughtherboss .88 and is provided with. azmetering.restrictiondl3..controlled by a needle valve :84. Valve .85 :has 'a stem 35 projecting -.oppositely, of tapped opening Si .in boss to and provided with-a collar .88 .between which and the adjacent :end offthe iboss .ther .is depressed a .coiled spring A which -.-constantly tends to move itheineedle': valve out ofiorifice :restriction .33. Conneating; with;.passageJ 82 to. the

.left of.restriction 83 .(Fig. 5) :therexisaninclined passagetd which connects with'ithe carburetor barrel at port it}. :Alsocextending from passage on the. right hand. SidBTOf: restriction r83 (Fig.5)

.is .a cross passaget l connecting by means .iof passage 82 .andiorifice restriction $l3wvithga vertical passage as which.joinssuctionpassage '12 previously mentioned opening into the :carburetor posterior-to the-i:throttle. IPassage H4 'is plugged at its upperend. 'Thepassa'ges ll; '12,

and 9d constitute a Y-shaped 'suctionmassage provided with an atmospheric bleed :through passages 3S and 82, the bleed being controlled'by needle valve "84.

For operating .needle valve 135, there is .provided a lever 96 '(Fig. :2) with ".afiESqlldIEdlOWGl extremity 9? 'pivotally mounted on Zthe outside of the carburetor body by ascrewf'QB. On the upper end of lever :sfi there is loosely swiveled .a small block SQarhaving '3fh01699b2fl11dTSCI'EW 990 for attachment .of :Bowden wire cable Hi9 (Figs. 1 and 3).. A curved lever :llll ;is*pivoted toth carburetor'body:byrmeans-of1a screw Hi2 and has parallel threaded1= ears J83 receiving adjusting screw I64 which bears against the squared lower extremity ll'l of lever .55. At the upper end of lever IIH there-isan extension I05 which rests against theextremity of needle Valve stem 85. Thus, pivoting .of lever .96 .in either direction urges the needle valve .84 toward its seating in orifice 83 an'd'hasthe effect-of re- .i-ilii,

toward itsv most restricting position.

ducing the amount of air bled into suction passages ti, 92, M, and i2.

Opposite curved lever it! there is provided a second, similarly shaped lever we pivoted to the carburetor body by means of a screw I09 and provided with threaded ears H0 receiving adjusting screw 1i! 5 which bears'against the. squared lower extremityof lever 58 opposite screw "it. Lever N38 has a downwardly projecting finger l l2 which abuts a log i it formed on an arm H4 rigid with the throttle shaft. The arrangement is such that upon rotation of lever 96, the throttle valve is moved .to 'a slightly-open position for starting.

Lever lid on thethrottle shaft is provided with sazfinger 'HE'Which engages a rib anism extending into the driver's compartment.

Curved, pivoted levers lill and W8 are yieldingly connected at their upper extremities by acoiled tension spring I22 which causes-screws it l and iii to bear against the cam forming lower extremity Moi lever 96. In the vertical position of lever Sides shownin Fig. 2,1needle valve 6-2- is withdrawn to its .m'a'ximum extent from its controlled 'orifice 83 and the throttle valv is permitted to reach its normalidling position which is determinedby engagement ofrib M6 by screw H8.

--.l1aft ii, previously 'mentioned as rigidly mountingzlever tit and main orifice valve 55,.ex-

tends beyond the cup-shaped casing '55 on the side or" the carburetor opposite .to lever '(Fig.

4), and rigidly mounts acurvedlever S25 :and loosely mounts a secondlever 26. Lever ifitis connected by. a-linkrifl'l toan'arm IE3 rigid with the throttle shaft opposite to control .lever .i M, Tight arm its "at. its 'extremity .re-

a pad I39 on loose lever I26. Bymeansof this arrangement, closing of'the throttle valve iurges shaft 5? in the counter-clockwise direction with relation to Fig. 4:. or in the clockwise direction with relation to Fig. 6, so as to move valve 55 Opening of the throttle yieldingly operates lever H5 and shaft in the opposite direction through a torsion spring i3i received about'the end of shaft This yielding operation permits closing of valve 55, to a greater extent than is justified by th throttle position, underithe influence of suction operated diaphragm St to provide an economizing effect during partthrottle operation.

The regulator, as shown diagrammatically in 3, is formed principally of a cylindrical casing I 35 with a web I35 extending thereaoross. To the left of this web there is a separately formed webstructure it? which is nested within and cooperates with the casing side walland web [35 to form a water chamber to which not water from the vehicle ooolingisystem is conducted by hoses 28 and 2? (Fig. 1) connected to fittings 438 and i353 (Fig. 3). Cap structure MU closes the left-hand end of the rcasing and a flexible diaphragm Mi is secured between web structure 131 and this cap structure. The diaphragm is constantly urged toward the left by means of coiled spring 142 seating against web 131. A

coil 1% is received between webs I36 and 431 with one of itsends connected to lovv'prese sure gas outlet 1 19 through :a radial orifice formaseat fora'valve ll-2. The other end of coil opens into first reduction chamber H58.

An inlet coupling structure on cap its is controlled by a high-pressure inlet valve Hi l oper atively connected to diaphragm will by means or" a lever Hi5 pivoted at His; to the cap structure and with its upper extremity hearing against an S -shaped spring i 51 projecting from. diaphragm MI. The arrangement is such "that gas inlet valve t may enter first reduction chamber 15% to exert its pressure on diaphragm 5M. When this pressure overcomes spring M2, the diaphragm urged-to the right and valve its is closed. "pressure gas from chamber 1 then enters heating co'il hit.

A second body structure We is attached to right 'handend of casing 135 and secures in posh tion a diaphragm Hill. A central opening it? in this body structure is closed "by a flexible diaphragm IE8.

A cap element are closes the right hand side of "body structure IE5 and secures in position athird operating diaphragm 76. A radial opensing Ill in the main casing provides for exposing the left hand side of diaphragm ace and chainher l-BB to the fuel pressure discharged past valve This valve is operated by angular lever al'l''pivoted at 133 on the casing.

Lever l'M has an arm use which, at its lower extremity bears against apiece Hill at the center of diaphragm Hit. This leverage arrangement is such that the low pressure gas applied to the left side of diaphragm that tends to close valve .112. A small coil spring ltll compressed between angular lever I'M and Web I 36 "normally urges the valve closed.

Central piece I88 on diaphragm 5% engages a similar piece HM at the center of diaphragm i653 which, in turn, engages a central actuator button 135 secured "to diaphragm Wt. Chamber its at the right side of diaphragm let connects with air vent tube 3% (Fig. 1) leading to air tube it at the inlet end of the carburetor. This chamber is also connected 'by'a cross passage (til to chamber I99 'at'the right hand side of diaphragm 5713. Both chambers [9t and Mil are substantially exposed to atmosphere as the reference pressure. Chamber 2% at the right hand side of primary diaphragm Ml is also exposed to atmosphere through vent Qillta. Chamber 2M at the left hand side of diaphragm lit connects with suction piping 2% leading to the carburetor mixture conduit posterior :to the throttle. Intermediate diaphragm Hit serves merely to separate chambers 19B and 29! so that lid can be en'ranged in the compact, side by side manner shown. Diaphragm may be con sidered as the secondary diaphragm or valve control and diaphragm He! serves as the idling and starting *valve control.

The relationship or" the various chambers and passages and the operation of the apparatus is most clearly illustrated in diagrammatic Figure 3 in which the various parts are designated by t e same reference numerals used in the previously described figures. A tank of butane or other normally gaseous 'fuel under pressure is connected to inlet 52, so that its pressure is applied to the left hand side of diaphragm t lt and the pressure in primary cha nber its is reduced and limited to about e /z pounds per square inch. "The fuel, in a liquid condition in tank.

2 0, vaporizes as it enters chamber 15.8. This-fuel is then lead through heating coil 1.43 to secondary, pressure reducing :and limiting valve I12, Since chamber IE5 at the leftside of diaphragm ace connected to outlet passage I 59 and thence by means of pipe 23 to the carburetor, operation of the engine draws gas from chamber E88 so as to reduce the pressure therein below the substantially atmospheric pressure in reference hamper was which results in leitwardmovement of diaphragm use and opening of secondary valve ill. Metering valve 55 constitutes a third pressure reducing and limiting valve in the system.

For starting, lever 56 is rotated bymeans of rod or Bowden cable JED so as to rotate curved lever I or and close bleed vent valve or and apply the full force of manifold suction to passage 2'9 and chamber 291 at the left hand side of diaphragm I'lfi. This diaphragm is "thus Urged leftwardly and through center screws 5'94 and tilt and lever iilli opens secondary "valve 412 against spring Hill to supply an extra charge of fuel for starting. Operation of hand leyergilfi also rotates curved lever H13 to :set the throttle valve in a slightly open position for starting. The engine starting speed may be adjusted by means of screw 5 i l and the regulator fuel delivery pressure by screw Hi l which determines the degree of closing of bleed vent orifice 83.. When engine fir s and runs, starting cable I Gil is released permitting opening of vent valve M "by means of its coil spring 8?.

During idling, very little suction is available through feed passage as which communicates with the fuel supply nozzles 4'! anterior "to the throttle lI-lowever, manifold suction is ccrnmu nicatcd through passages 72 and 2-9 to the left hand side of diaphragm Hi! as in starting, to shift this diaphragm and provide sufficient fuel for idling. At this time, lever lit connected to throt"le lever i255 holds main supply valve 55 in its most restricting position. The regulator is adjusted with relation to this minimum valve opening so that during idling, a slightly superatmospheric pressure is supplied through pos sage 2'53 and fills carburetor ante-chamber immediately adjacent the main supply nozzles and this pressure may be adjusted according to and acceleration requirements by varying the area ratio of restrictions 33 and 93.. Thus, upon acceleration, when suction at the nozzle is relatively low, a volume of fuel is available to provide the extra richness necessary at this time. The minimum area of the annulus between valve and orifice 56 may be adjusted by means of screw are (Fig. 4)

During so-called economy range operation, when the engine is operating under light load with the th ottle in only partially open position,

manifold suction is transmitted through passages l2 and H to economizer diaphragm chamber is so as to urge tight lever $.25 through link 63 in a direction to urge valve 55 closed, torsion spring lei flexing to permit this. During slow idle and early part throttle operation, and until diaphragm llll has reached the limit of its stroke toward the left, the superatmospheric pressure existing in passage 23 and ante-chamber is controlled by balancing of the force exerted by diaphragm Hi3 toward the left against the force exerted by the pressure in pipe and chamber its which urges diaphragm his to the-right. Metering of the fuel during this period "is accomplished by the variation of the annulus formed by orifice 5t and valve 55, according to throttle movement, and variation of pressure drops across orifice 54 produced by varying air flow through the carburetor. When idling and starting diaphragm IIfl reaches the limit of its useful stroke to the left, or when insufficient manifold depression is available to exert an appreciable force on diaphragm I70 through passage 29, carburetor suction transmitted through passage 28 actuates secondary diaphragm I86 and valve I I2 to supply gas at a substantially constant sub-atmospheric pressure. Obviously, reduction of the pressure within secondary chamber I86 also reduces pressure in primary chamber I58 so as to permit additional opening of valve I54 and the entry of additional quantities of fuel from the main tank.

The above apparatus, accordingly, is well adapted to supply fuel in the proper quantities with relation to the air drawn through the carburetor for operation of an automotive engine and to respond promptly and accurately to varied conditions of speed and loads applied thereto. Since primary and secondary gas valves I53 and I12 are normally closed, leakage of gas is prevented When the engine i not in operation. The various parts are arranged so as to fit compactly within the regulator and assembly is greatly facilitated and simplified.

The invention may be modified in various respects as will occur to those skilled in the art and the exclusive use of all the modifications as come within the scope of the appended claims is contemplated.

We claim:

1. A gas carbureting apparatus for an engine comprising a mixture conduit having a throttle, a supply passage for connecting said conduit anterior to said throttle to a source of normally gaseous fuel under pressure, a pressure regulator in said passage constructed and arranged to deliver fuel to said conduit inversely in accordance With pressure changes in said passage, a suction connection between said regulator and said conduit posterior to said throttle to modify the action of said regulator, an air bleed in said suction line, and a manual, remotely controlled valve for said bleed to vary the effectiveness of said connection.

2. A gas carbureting apparatus for an engine comprising a mixture conduit having a throttle, passage means for supplying normally gaseous fuel under pressure to said conduit anterior to said throttle, a pressure regulator in said passage means spaced substantially from said conduit, a control valve in said passage immediately adjacent said conduit, a pressure responsive device for actuating said control valve, a suction passage connecting said conduit posterior to said throttle to said regulator and said device for operating the same, an air bleed vent in said suction passage, and a manual, remotely operated valve controlling said vent for varying the effectiveness of said suction passage.

3. An apparatus as described in claim 2 adapted for use with an automotive vehicle and further including means extending to the drivers compartment to facilitate actuation of said valve in starting.

4. Gas carburetion apparatus comprising a mixture conduit having a fuel nozzle and a throttle, a fuel delivery passage connected to said nozzle, a first fuel supply control valve in said passage and adjusting means therefor including a pressure chamber with a movable wall oppositely exposed to a reference pressure and a fluid pressure connection to said mixture conduit, suction modulating means for said connection, stop means for limiting closing movement of said throttle to a starting position, a remote control device for joint manual actuation of said modulating means and said stop means for starting purposes, a second fuel supply control valve in said fuel passage adjacent said nozzle, and an operative connection between said second control valve and said throttle.

5. A gas carbureting apparatus for an engine comprising a mixture conduit havin a fuel nozzle and a throttle, a passage for supplying normally gaseous fuel to said nozzle, a fuel valve in the junction between said passage and said nozzle and controlling the passage of fuel through said nozzle, a device having an expansible and con tractible chamber with an operating suction connection to the mixture conduit and operatively connected to said valve, an air bleed for said suction connection, a control valve in said air bleed, and an operative connection between said control valve and said throttle.

6. A gas carbureting apparatus comprising a mixture conduit having a throttle and a nozzle, a fuel supply passage for connecting said nozzle to a source of normally gaseous fuel under pressure, a valve in said passage immediately adjacent said nozzle, a pressure regulator in said passage upstream of said valve includin a second valve and an expansible chamber having a movable Wall operatively connected to said second valve, a fluid pressure connection between said chamber and said mixture conduit, and means for controlling said first valve including an operative connection between said first valve and said throttle, a second expansible chamber having a movable Wall exposed to pressure conditions in said conduit, and an operative connection between said. first valve and said second movable wall cooperating with said throttle in controlling said first valve.

7. A gas carbureting apparatus for an engine comprising a mixture conduit having a main fuel nozzle and a throttle, a source of normally gaseous fuel under pressure, a fuel passage connecting said source and said nozzle, a regulator for said passage including a first valve and a suction motor comprising a movable wall actuator operatively connected to said valve and opposing reference and control pressure chambers, one exposed to the fuel pressure in said passage and the other to a reference pressure, a second valve in said passage between said nozzle and said first valve, an operative connection between said second valve and said throttle for closing said second valve to idling position to supply only sufiicient fuel for idling when said throttle is closed, and means for increasing said reference pressure when said throttle is closed so that said first valve Will remain partially open during idling and thereby pass slightly more fuel than said second valve to increase the fuel pressure between said valves and insure an extra supply of fuel to said mixture conduit upon initial opening of said throttle and said second valve for acceleration, said last means comprising a suction connection between said reference pressure chamber and said mixture conduit posterior to said throttle, a third valve constituting a control for said last connection, and an operative connection between said last mentioned valve and said throttle adapted to close said last valve as said throttle is closed to thereby increase said reference chamber pressure.

8. Apparatus as described in claim '7 in which said fuel passage includes an enlarged chamber portion for storing an extra supply of fuel for acceleration.

9. Apparatus as described in claim '7 in which said reference pressure increasing means further includes an air bleed for said suction connection, said third valve bein in said air bleed and being actuated by said throttle when opened beyond the idling position for restricting said bleed to thereby increase the effectiveness of said suction connection upon said reference pressure.

10. Apparatus as described in claim 7 in which said second valve has a lost motion operative connection to said throttle and further including an expansible chamber device responsive to the pressure differential between mixture conduit suction posterior to said throttle and the pressure in said fuel passage for opening said second valve as the fuel passage pressure decreases, to the degree permitted by said throttle connection.

JAMES F. ARMSTRONG. JAMES T. W. MOSELEY.

References Cited in the file of this patent UNITED STATES PATENTS Number 

1. A GAS CARBURETING APPARATUS FOR AN ENGINE COMPRISING A MIXTURE CONDUIT HAVING A THROTTLE, A SUPPLY PASSAGE FOR CONNECTING SAID CONDUIT ANTERIOR TO SAID THROTTLE TO A SOURCE OF NORMALLY GASEOUS FUEL UNDER PRESSURE, A PRESSURE REGULATOR IN SAID PASSAGE CONSTRUCTED AND ARRANGED TO DELIVER FUEL TO SAID CONDUIT INVERSELY IN ACCORDANCE WITH PRESSURE CHANGES IN SAID PASSAGE, A SUCTION CONNECTION BETWEEN SAID REGULATOR AND SAID CONDUIT POSTERIOR TO SAID THROTTLE TO MODIFY THE ACTION 